Ultrasonic control unit for a travelling cutter

Claim 1

An ultrasonic control unit for a travelling road grooving machine (1) comprising a cutter drum (2), which is supported for rotation relative to said road grooving machine (1), and front and rear travelling gears (3, 4), one (4) of said travelling gears being provided with a first travelling gear height adjustment means controlled in dependence upon a cutting depth control signal, characterized in that: the other traveling gear (3) is provided with a second travelling gear height adjustment means; at least three ultrasonic sensors (10, 11, 12) are arranged on the road grooving machine (1) one behind the other essentially in the direction of motion of said road grooving machine (1); an evaluation means (15) is provided for detecting the distances (s1, s2, s3) between the ultrasonic sensors (10, 11, 12) and a reference surface on the basis of ultrasonic sensor signals of said ultrasonic sensors (10, 11, 12); that the evaluation means (15) being adapted to derive from said measured distances (s1, s2, s3), on the one hand, an inclination signal representing the angle of inclination of the cutter (1) relative to the reference surface and, on the other hand, an averaged distance signal (dm); and the evaluation means (15) being further adapted to derive control signals for the two travelling gear height adjustment means from said averaged distance signal (dm), from the inclination angle, and from a nominal cutting depth which can be adjusted.